Rome has a glittering history. Its empire lasted for a thousand years, its great emperors are famous still today. But Rome had a bad side to it. If we could time-travel back to Rome today we would not like everything we would see.

Slavery

The Romans kept slaves. All the hard work all over the empire was mostly done by slaves. They worked the farms, they cleaned the sewers, they were the servants in the wealthy houses. They belonged to their owners as though they were animals. Just like animals they could be bought and sold, punished and whipped by their masters.

Bloody Games in the Circuses

When the Romans went to the circus to watch the games, it was to view a brutal spectacle. Chariot racing was perhaps the least murderous event - although many drivers were hurt in spectacular crashes. But for more gruesome entertainment the Romans watched wild beasts tear each other apart, or gladiators fighting exotic beasts from far away countries, or gladiators fighting each other to the death.

Mad emperor Caligula

Insane Emperors, Cruel Emperors

Also, some of their emperors were maniacs. The most famous was Nero (see Famous Romans) but there were many others. Sometimes even the good emperors needed first to be utterly brutal in order to take power. Brutality was often the order of the day. More so of course, when mad or just particularly cruel emperors came to power.
Mad emperor Caligula ordered his legions to collect shells on the beach in order to prove that he had "conquered the sea". Nero killed his mother and his wife. And the cruel emperor Septimius Severus had the body of his dead opponent Clodius Albinus laid out before him, so that he could ride over it with his horse.
These are just some examples of Roman madness and Roman cruelty by its own emperors.

Ordered Suicides and "Proscription"

If an emperor wanted rid of a particular senator, he would simply write him a letter, ordering him to kill himself (or else he would send someone round to kill him). Emperor Nero ordered a great many such suicides.
The dictator Sulla during the time of the Roman republic invented the "proscription", by which he would just announce whom he wanted dead. This would be read out in public places and he then would reward anyone who would kill that particular person.

Nero
Capitoline Museums
Rome

Religious Persecution

Rome was brutal in its enforcement of its religious views. Several wars were fought with the Jews in order to try and get them to accept the worship of the deceased Roman emperors as gods. The fighting was so fierce, the great city of Jerusalem was destroyed, and with it the ancient temple of Solomon was razed. Most famously, the Christians were thrown to the lions by emperor Nero who blamed them for the Great Fire of Rome.
Later, after the empire had been christianized, the believers in the old Roman gods were equally persecuted by the Christian emperors.
And so too the various heresies (misteachings of Christianity) were persecuted violently by Roman rulers.

So what we always must keep in mind when we read about the Romans is that they were a fairly brutal and sometimes gruesome lot.